Electron switch, structures, and circuits



June 12, 1951 I HCLARK 2,556,166

ELECTRON SWITCH, STRUCTURES, AND CIRCUITS Filed March 20, 1947 v 2 Sheets-Sheet 1 gvwa/Mov Tlefl/ok H. CL/IRK FIG. 5

June 12, 1951 T, H, CLA K 2,656,166

ELECTRON SWITCH, STRUCTURES, AND CIRCUITS Filed March 20, 1947- Z'Sheets-Sheet 2 Patented June 12, 1951 ELECTRON SWITCH, STRUCTURES, AND CIRCUITS Trevor H. .Clark, Boonton, Morris County, N. J., assignor to International Standard Electric Corporation, New York, N. Y., a corporation of Delaware I Application March 20, 1947, Serial No. 735,953 In France February 27, 1939 Section 1, Public Law 690, August 8, 1948 Patent expires February 27, 1959 6 Claims. 1

The present invention relates to electron discharge devices and circuits employing same, particularly those devices of the kind in which the electron flux is formed into an electronic beam, this beam being deflected to strike at different points of a collecting structure with a suitable focus on eachpoint of impact.

It is one of the objects of the present invention to provide electron discharge device structures in which it is unnecessary in order to obtain a high current toapply high potentials to themeans for concentrating the electronic flux, as is usually the case when electronic optical systems with concentration lenses are employed creating fields of continuously increasing intensity, While ensuring a suitableooncentration of the beam at any point of impact on which the deflecting or dividing means provided may guide Another object of the invention is to provide electron discharge device structures in which a small number of electrodes only is employed to concentrate and deflect the electron beam, for example, two electrodes in the case of a deflection of the beam in two dimensions and three electrodes in the case of a deflection of the beam n thre mensions- A further object of the invention is to provide means so that the deflection of the beam in such structures may be possible, not only to bring the beam from a collecting element or point to the adjacent point, but in any desirable manner.

It is still another object of the invention to provide utilisation circuits of such electron discharge devices for the connection of one circuit to another circuit among a plurality of others without the intervention of mechanical actions.

It is still another object of the invention to provide connection circuits employing such electron discharge devices in Which the connection is determined by impulses received by the discharge device emp'loyed, these impulses being transformed into fixed potentials applied to the deflecting means of said devices, or in another Way, connection circuits employing such devices with electronic beam as connection selecting elements.

In accordance with certain characteristics of the ihvention' an electron discharge device com Ill prises means for generating an electronic beam, means for guiding and concentrating this beam along a curved path to a collector arrangement consisting of a certain number of separate elements and means for deflecting this beam so as tocontro'l its incidence on one of the collecting elements as desired.

In accordance with another characteristic of the invention, these guiding and concentrating means of the electronic beam consists of two plates in the form of co-axial arcs of cylinders, and the required deflection is given to the beam by modifying the potential applied to one or both of these plates.

In accordance with another characteristic of the invention, these guiding and concentration means consist of two pairs of plates in the form of co-axial arcs of cylinders arranged at a certain angular distance from each other, means such as plate electrodes being provided inorder to direct the beam as desired between either of these pairs of plates, the deflection in either position of the beam being determined either by variation of potential of these initial pairs of plates or by variation of potential of these initial guiding means of the beam.

In accordance with another characteristic of the invention, these guiding and concentration means consist of a certain number of pairs of plates curved-in as described, and arranged around beam generating means, means being provided to direct the beam between the required pair of plates.

In accordance with another characteristic of the invention, the inside plates of these pairs of plates may form a part of the means for generating said beam.

In accordance with another characteristic of the invention, the collector elements are arrange-d at the ends of the pairs of plates in the form of straight or curved conducting bands.

In accordance with other characteristics of the invention, connection circuits for establish? ing connections in accordance With a selective control of the deflections of the beam in devices such for example as above, comprising a circuit to receive impulses, and means for transforming said impulses into constant control potentials, three for example, with a view to their application to a beam electronic discharge device, this 3 device being adapted so that the beam has a single starting or rest position, and a predetermined sequence of positions by deflection for a corresponding sequence of control potentials derived from the received impulses.

In accordance with another characteristic of the invention the incoming impulses are applied to a relay of which a set of contacts controls the electrodes for vertical and horizontal deflection of the beam, while another set of contacts controls the radial deflections of the beam, a condenser in parallel with a triggering discharge device being inserted between this latter set of contacts and the corresponding deflecting electrodes of the electron beam device, while the first set of contacts is connected to two devices forv metering the impulses in series, the first device being actuated by each impulse, and the second only being influenced by a pair of impulses, and each of these devices being individually connected to the electrode for vertical and horizontal deflection respectively of the electronic beam device.

In accordance with another characteristic of the invention, a circuit and device of this kind may be employed as switches without inertia for automatic telephone systems and the like.

The invention will be explained in detail in the following description given in connection with the attached drawings in which:

Figure 1 shows the concentration means for the electronic beam employed in the present invention.

Figure 2 shows a schematic example of an electron beam device incorporating characteristics of the invention.

Figure 3 gives an example of a modification of the device of Figure 2.

Figure 4 shows another example of an embodiment of an arrangement incorporating characteristics of the invention, and

Figures 5 and 6 represent two modifications of the device of Figure 4.

Figure '7 shows the manner in which the defiection of the beam can be controlled in a device incorporating characteristics of the invention.

Figures 8 and 9 respectively show in plane and in section another embodiment of an electronic beam device incorporating characteristics of the invention.

Figures 10 and 11 show various arrangements of collector elements of devices incorporating characteristics of the invention, and

Figure 12 shows an example of a control circuit of a device such as that shown in the preceding description and described in the specification.

Referring to Figure 1, the structure represented shows an electron emitting element I, such as a hot cathode, of which the emission is limited to one surface only by the electrode 2 which is kept at the potential of the cathode I, or at a potential of nearly the same value. This electrode 2 consists of a cylinder of the same axis as a longitudinal axis of the cathode, and having an opening in front of the surface of the cathode of which the emission is to be employed. Coaxial with this electrode is another cylindrical electrode 3 having an opening inline with the opening of the electrode 2, and which is brought to a suitable potential to accelerate the electrons emitted. Two cylindrical coaxial plates 4 and 5 are arranged so that the electronic flux of the cathode l passes between them, the axis of the electrode unit I-2-3 being half-way between the two plates 4 and 5.

These plates are extended on a length of curve of about 127 in order to obtain the concentration effect which will be described further on. A plate 6 is arranged across the end of the plates 4 and 5. The plate 4 is kept at a positive potential with respect to the cathode, and the plate 5 at a negative potential, zero or slightly positive with respect to the cathode which ensures an effective concentration of the electronic beam on the plate 6.

' The electrons emitted by the active surface of the, cathode I are accelerated by the cylinder 3 brought to a positive potential with respect to the cathode. The plate 4 is kept at a suitable positive potential for the desired operation, ifor example, between 50 and 500 volts with respect to the cathode, The plate 6 is kept approximately at the same potential as the plate- 4, although it may vary within wide limits. The potential of the electrode 5 in an embodiment of the present application has been taken as variable potential in order to control the deflection of the electronic beam. For a potential of 175 volts with respect to the cathode of the electrode 3, of volts of the plate 4 and +300 v. of the electrode 6, for, a variation of potential of the electrode 5 from zero to volts the beam was deflected by a distance equal to the width of the plate 6, the direction of defiection being towards the plate 5. The width of the trace of the beam has been found to be substantially equal to the width of the emissive portion of the cathode. For a cathode width of 2 mm; and a width of the plate 6 of 9 mm. the beam could easily be brought to three separate points on which it was concentrated, as mentioned above, and consequently said plate 6 might be divided up into three separate segments and the beam might be deflected from one of these segments to the other without overlapping. An arrangement of this kind is shown in Figure 2. 1'

In Figure 2 those elements similar to those of Figure 1 are given the same references, as is also the case with the various figures, of the drawings. The plates 6a, 6b and 6c are the collecting electrodes. The plate 5 may be connected to a potential which is either positive, negative or zero with respect tothe cathode, and is the only deflecting electrode of the structure.

Although in this drawing the plates 6a, 6b and 60 have been indicated as consisting of plane electrodes, it may be preferable, in accordance with another characteristic of the invention, to reduce the secondary emission effects of these plates and, consequently, to employ forms of collecting electrodes provided for this purpose, for example, as shown in Figure 3 these collecting electrodes may consist of channels.

Figure 4 shows another embodiment with electronic beam incorporating characteristics of the invention. This arrangement comprises a cathode I of which the thermionic emission is confined to one surface only by the action of the cylindrical electrode 2. The electrode 2 is surrounded by a coaxial accelerating electrode 3. On each side of this unit are arranged electrodes 4a and 4b playing the same part as the electrode 4 of the previous drawings, and the electrode 5 has with respect to the plane of symmetry of the whole a symmetrical form composed of two cylindrical arcs respectively, coaxial with the cylinders 4a and 4b. In this case one of the potentials applied to one of the electrodes 4a or 412 is slightly greater than the potential applied to the other so as to give the electronic beam emitted by the cathode I a normal position to the right or left of the structure. In another manner the potentials applied to the electrodes 4a and 4b are strictly equal, but the electrode is'no longer symmetrical, but slightly eccentric in the desired direction and with respect to the plane of symmetry'of the assembly of the other electrodes of the structure. A control of the initial position of the beam, or even of its position in operation could be obtained by displacing the electrode 5.

The potentials applied to the various electrodes may be in proportions corresponding to those already indicated for the device of the previous figures. The radial deflection of the beam may be controlled by the electrode 5 in the manner described. Moreover, it is clear that in the various arrangements shown, the potentials of the electrodes 4 and 5 may both be modified in order to obtainsuch control of the beam, the whole of these electrodes always ensuring an effective concentration of the beam, and focussing to an angle of 127 from its origin. In the'structure of Figure 4 two additionaldefl'ecting electrodes 1a and 1b are shown in the form of plates for example. These electrodes, moreover, might consist of bars or grids of any suitable structure. The electronic beam will then be deflected to the right or left in consequence of the {relative potentials applied to the electrodes la and 1b,the potentials applied to the electrodes 4a and 4?) then being equal.

Since the first concentration by the electrode 2 is provided in such a way that the electrode 3 receives no electronic current, this electrode in accordance with another characteristic of the invention may be eliminated and the deflecting plates Ia and 1b may be used at the same time for the deflection and acceleration of the electronic beam. A structure of this kind is shown in Figure {5 and has the advantage of reducing the number of current leads.

An advantage of this kind can, moreover, be

carried even further in accordance with other characteristics of the invention by eliminating the deflecting plates 1a and 1b and establishing on the electrodes 4a and 4b potentials such that these'electrodes play the triple part of elements for concentration of the beam in co-operation with the electrode 5, for acceleration of the beam leaving the electrode 2, and for deflection of thebeam to the right or to the left. The arrangement of this kind is shown in'Figure 6.

In'the arrangements of Figures 4, 5 and 6 the collecting electrodes are shown in the form of crosswise plates, three for each side of the structurfe,j'6a -6b-6c and 6d--6e-6f respectively.

'Inorder to apply a deflecting potential to the plates 1a and 1b any suitable circuit may be employed for example, that shown in Figure '7 which consists of a valve V and a resistance R between the two plates la and lb.

'It is clear that with the arrangement of Figures 4, 5 and 6 an electronic switch has been obtained without inertia with six positions. This number of positions may be increased as desired, either bymultiplyng the plate segment 6 for each semic'ylindrical structure, or by increasing the number of these semi-cylindrical structures, or both.

In Figures 8 and 9, Figure 9 being a section along arra of Figure 8, an electronic switching device with twelve positions is shown respective ly in plane and in section. It should be underg "stood that although these figures show a doublesymmetry device it is clear that any polygonal arrangement may be obtained from Figure 2. This arrangement may only in fact bepolygonal by the arrangements of collecting electrodes, a circular symmetry preferably being obtained for the electrode 5 which may be in the form of a fragment of toroidal surface with zero internal radius and the electrode 4 which consists of a complete torus. However, it is clear that these electrodes might be obtained so as to conform with the polygonal symmetry of the collecting electrode arrangements 6. 1 I

In order to refer to the structure of Figures 8 and 9 by way of illustration, the generator and accelerator unit of the electronic beam consist of an electron gun composed in the usual yvay of a cathode I, a cylinder 2, and an accelerating electrode 3, or any other special structure. Deflecting electrodes in two pairs '|--l ,and 8- 8 are provided in the case under consideration in order to supply 4 directions of deflection" of the beam. Four arrangements of three collecting electrodes 6 are indicated at right angles to each other facing the pairs of plates l--1; and 8- 8. The operation of a device of this kind'is. clear, in accordance with the operation of the devices previously described in the specification. I

With a device of this kind it is, consequently,

clear that the electron beam emitted by the electrode I may be caused to fall on any desired one of the electrodes 6 which are maintained ordinarily at a positive potential although this potential is not necessarily the-same for'all the collecting electrodes. These assemblies of collecting electrodes'may be of any desired arrangement, for example, may

be as shown on one of Figures 10 and 11 for -a 12 position switch. They might be arranged in similar manner for a switch with any necessary number of positions.

For the arrangement of Figure 10 it will be sufllcient to contifcl the application of one of two potentials between two of the pairssi'milar to the electrodes l- -,'I, 8-'8 and collecting electrode 6, moreover, depends upon the choice of the control potentials and the rest of the control operations required.

"The arrangement of Figures 8 and 9 with-a collecting arrangement such as thatot Figure 11 will be considered by way of example in" the control system shown schematically in Figure 12 for a marker switch system of automatic telephony. This use of a marker switch is not limited to th' use of electron beam devices incorporating characteristics of the invention, but it should be un derstood that on the contrary it is only given by way of illustration, and that such devices may be employed for any use of selective switcher: which may be conceived in the field of electrical connections in remote communications or corn trol, for example.

thQxGQIltIOI of a circuit connected to the electrode of the radial deflection device, or electrode.

When these contacts 24 are closed-the condenser 25 is charged by the battery 26 through c resistance 21. The potential measured on the terminals of the condenser 25 increases in bounds in accordance with the capacity of the condenser 25, the value of the resistance 21 the potentiai of the battery 26 and the number of impulses transmitted to the relay 22 These constants and. the critical potential of a gas relay 28 are determined in such a way that, when thecontacts 2% have, been closed twice, the gas relay has not been rendered conductive, but that, when these contacts have been closed three times, the gas I relay is always rendered conductive. In other words, any speed of operation ofthe dial Elbetween .5 and periods per second will charge the condenser connected with the gas relay 28 at a potential lower thanthe potential of discharge in two impulses and greater than this potential of discharge in three impulses.

The potential on the terminals of the gas relay 28 is also applied by the connections 29 to the electrode 5 of the electron beam device. When the condenser has not been-charged by an -t o nornial and the cycle begins again. The cycle of deflection of the beam may be reversed, ob-

viously, but the rest of the explanation will take into consideration what has been described.

When the upper contacts of the relay 22 are opened the condenser 36 is charged by the battery 3| through the resistances 32 and 33, the

resistance 33 being small with respect to the resistance; 32. When the contacts are closed the condenser is rapidly discharged through the res'istance'33 and the contacts of relay 23. The result is on the terminals of the resistance 33 ing device 35 is actuated by the first, and is arranged so as to be actuated by-an impulse every ,time the former returns to its normal position.

other words, the original position of this metering arrangement is not disturbed until the reception of the second impulse from the dial. This second impulse will modify its position and, consequently, the horizontal deflection of the electron beam. I

{Ihese metering devices may consist of any device which divides the'input frequency in two. For example, they may each consist of two vacuum tubes mutually interconnected by connection of the plate circuit of the one with the grid circuit of the other, and this in such a way that the ratio of division of the frequency (2 in-the case desired) is independent ofthe input frequency.

Consequently; supposing that the normal tion of the beam be vertically upwards and horiz ontally to the lright, upon each impulse received from the dial the beam will reach the electrode designated in Figure 11 by the number of impulses received. The displacements ofthe beam are indicated in the following table;

Vertical Deflection Radial After impulse N 0. Deflection 0 Interior...

Centre.. L

Exterior... Interior... Centre...- Exterior... Interior... Oentre.... Exterior... Interior... Centre.... Exterior...

High Low It will be seen from Figure 11 that the beam is successively displaced from one electrode to another, so that" it does not strike twice .on an electrode before it has passed over all the others,

and it will be maintained stationary on an electrode correspondin to the number of the last .impulse received; The beam always leaves the electrode No. 0 and if, for example; six impulses are sent by the dial 20, it will be brought to rest on electrode No.16 after having passed over all the electrodes I01, I02, I03, I04, I05. electron switch of low inertia is obtained. A switch of this kind can, of course, be applied to all practical kinds of switching controlled by impulses, for example, for automatic telephony, remote control, etc. 7

Although the invention has been described in detail in certainaembodiments, it is clear. that it is in no way limited thereto, but on the other hand, is capable of numerous modifications-and adaptations without departing from its scope.

I claim: .1. An electron discharge device for deflecting an electron beam, comprising a source of electron emission, a cylindrical electrode disposed about said source having.- an opening in a given direction for limiting theemission of electrons to said direction, electron accelerating electrode means disposed in close proximity to said source, two pair of electrodes for deflecting and concentrating the'electron emission, one pair disposed on one side of said sourcewith respect to the undeflected line of electron emission and the other pair disposed on the other side of said source, one of each of said pair of electrodes having a cylindrical and the other an arcuate form, each pair being coaxially related, and electron collecting electrode means between each of said pair of electrodes and spaced from said source.

2. An electron-discharge device for deflecting an electron beam comprising a source of electron emission, a cylindrical electrode disposed about said source having an opening in a given direction for limiting the emission of electrons to said direction, electron accelerating electrode means disposed in close proximity to said source, a pair of electrodes for deflecting and concentrating the electron emission disposed about the axis of emission, one of said electrodes forming a cylindrical torus, the second electrode forming an arcuate portion of a torus having a substantiallylzero inside diameter in coaxial relationship to the line of emission, electron beam deflecting elec- Thus, an

trodes disposed in correlated pairs about the line of emission, and electron emission collecting electrode means radially disposed about said source and between said pair of electrodes.

3. An electron discharge device according to claim 2 further comprising deflecting electrodes mounted one on each side of the undefiected line of emission and positioned between said source and said pair of electrodes.

4. An electron discharge device having an envelope enclosing a cathode for supplying electrons, a cylindrical electrode disposed about said cathode and having an opening in a given direction for limiting the emission of electrons to said direction, electrode means adjacent said cylindrical electrode for accelerating said electrons in said direction, a pair of part-cylindrical electrodes for concentrating said electrons after leaving said accelerating electrode, said part-cylindrical electrodes being coaxial and having their axes perpendicular to the path of said beam, one of said part-cylindrical electrodes being positioned on one side of said cathode and the other partcylindrical electrode being positioned on the other side of said cylindrical cathode whereby said electrons enter the space between said partcylindrical electrodes and at least one output electrode positioned between said part-cylindrical electrodes substantially 127 removed from said cathode.

5. An electron discharge device having an envelope enclosing a cathode for supplying electrons, means adjacent said cathode for forming the electrons into a directed beam, a first arcuate electrode disposed on one side of the path of said beam and having its axis perpendicular to the path of said beam, at second arcuate electrode coaxial with the first arcuate electrode and dis- 10 posed on the opposite side of the path. of said beam and an output electrode position between said part cylindrical electrodes substantially 127 removed from said cathode.

6. An electron discharge device having an envelope enclosing a cathode for supplying electrons, means adjacent said cathode for forming the electrons into a directed beam, a first pair of oppositely curved part cylindrical electrodes having their axes perpendicular to the path of said beam and. parallel to each other, a second pair of at least part cylindrical electrodes each coaxial with one of said first pair of part cylindri cal electrodes and spaced therefrom, an electron collecting electrode mounted between each of the coaxial electrodes and spaced from said cathode and means for selectively deflecting said beam into the space between either pair of coaxial electrodes.

TREVOR H. CLARK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,144,085 Rothe et al Jan. 17, 1939 2,146,607 Van Overbeek Feb. 7, 1939 2,159,774 Veenemans et al. May 23, 1939 2,254,096 Thompson Aug. 26, 1941 2,256,301 Wagner Sept. 16, 1941 2,272,165 Varian et a1 Feb. 3, 1942 2,293,417 Thompson Aug. 18, 1942 2,380,225 Fleming-Williams July 10, 1945 2,395,299 Skellett Feb. 19, 1946 2,477,008 Rosen July 26, 1949 

